Multiprojectile cartridge with gas tapping means



April 21, 1964 F. P. REED MULTIPROJECTILE CARTRIDGE WITH GAS TAPPING MEANS Filed March 14, 1963 Fig.1

2 Sheets-Sheet 1 INVENTOR.

April 21, 1964 F. P. REED 3,129,664

MULTIPROJECTILE CARTRIDGE WITH GAS TAPPING MEANS Filed March 1-4, 1963 2 Sheets-Sheet 2 IN VENTOR. FIEd Eli EkP REEd:

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United States Patent M 3,129,664 MULTIPROJECTILE CARTRIDGE WITH GAS TAPPlNG MEANS Frederick P. Reed, Ludlow, Mass, assignor to the United States of America as represented by the Secretary of the Army Filed Mar. 14, 1963, Ser. No. 265,603

4 Claims. (Cl. 10238) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to cartridges and more particularly to cartridge with a plurality of projectiles for use with a multibore barrel.

The invention of a method for manufacturing a satisfactory gun barrel with a plurality of bores, as described in the patent application entitled Method of Manufacturing a Multibore Barrel, by Joseph R. Eves, Serial No. 257,824, filed February 8, 1963, has stimulated research into the design of a cartridge and a firearm operating mechanism for use with such barrel.

One of the problems involved has to do with the use of such a barrel with a gas energized firearm operating mechanism as the structure of a multibore barrel makes it difficult to form a system of gas conduction which provides sufiicient gas pressure to energize the inherently massive operating mechanism for semi and fully automatic weapons.

Another problem has to do with the obturation of the projectile carrying insert in the cartridge with the barrel bores and the retention of the insert in the cartridge case during ejection as residual gas pressure in the case tends to force the insert therefrom, which would cause fouling of the breech mechanism.

It is, therefore, one object of this invention to provide a multiprojectile cartridge having means for tapping oil gas at peak pressure into a conduit in the firearm barrel.

It is another object of this invention to provide such a multiprojectile cartridge with means for obturating the projectile carrying insert and barrel and retaining the insert in the fired case against the force of any residual pressure therein during the ejection operation.

The specific nature of the invention, as well as other objects and advantages thereof, will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a longitudinally cross-sectioned view showing the breech end of a firearm barrel with one modification of the cartridge of this invention chambered therein;

FIG. 2 is a view taken along line 2-2 of FIG. 1;

FIG. 3 is a view taken along line 3-3 of FIG. 1;

FIG. 4 is a view similar to FIG. 1 but showing another modification of the cartridge of this invention; and

FIG. 5 is a view taken along line 55 of FIG. 4.

Shown in FIGS. 1-3 is a cartridge 12 which is received for discharge by a chamber 14 in a barrel 16 having three symmetrically disposed bores 18 formed therein and an axial conduit 20 for conducting discharge gases to a gas energized operating mechanism (not shown). Cartridge 12 includes a case 22 and an insert 24 which is fitted into the front section thereof. A compartment 26 for a propellent 28 is formed in case 22 rearwardly of insert 24. The front edge of case 22 is crimped at 30 for restricting forward displacement of insert 24 from the case.

Insert 24 is provided with three holes 32 which are arranged so as to be coaxially alignable with bores 13 and 3,129,664 Patented Apr. 21, 1954 each of the holes receives a projectile 34. A port 36 extends coaxially from the front end of insert 24 to a wall 38 so as to be in coaxial alignment with conduit 20 when cartridge 12 is received by chamber 14. Wall 38 is spaced a predetermined distance from the rear end of insert 24 to form a diaphragm 40 which is designed so as to be ruptured by the discharge gases when approximately at peak pressure to permit passage of the gases through port 36 into conduit 20.

Provided in the front face of insert 24 is an annular groove 42 which intersects the front ends of the holes 32 so as to provide intercommunication therebetween. Groove 42 forms a forwardly facing surface 44 which converts gas pressure received by the groove to a rearward thrust against insert 24 and thereby assists crimp 30 in preventing forward displacement of the insert from case 22, by the residual pressure in chamber 26, during ejection of the case from chamber 14.

Shown in FIGS. 4 and 5 is a cartridge 50 which illustrates still another embodiment of the invention. Cartridge Si is similar to cartridge 12 and like members have been given like reference numbers on the drawings. The difference between cartridges 12 and 5!) lies in the configuration of the insert. Cartridge 50 includes an insert 52 having three holes 54 which have the same functions as holes 32 in cartridge 12. concentrically formed in the front face of insert 52 is a circular recess 58 which is arranged to intersect holes 54 at the front ends thereof and form thereat apertures 69 for bleeding gases from the holes, approximately where peak pressure is achieved, into the recess and therefrom into conduit 20. Recess 58 forms a forwardly facing surface 62 which converts gas pressure in the recess to rearward thrust against insert 52 for partially overcoming any residual pressure in compartment 26 during ejection of case 22 from barrel 16.

Thus, when cartridge 12 is discharged, the pressure of the gases in compartment 26 forces insert 24 forwardly against the front face of chamber 14 to obturate the junction of holes 32 with bores 18. When projectiles 34 are propelled from holes 32 into bores 18, and the discharge gases are approximately at peak pressure diaphragm 40 ruptures to discharge the high pressure gases through port 36 into conduit 20 for energizing the firearm operating mechanism (not shown). When projectiles 34 enter bores 18, the discharge gases in annular groove 42 act upon surface 44 to assist in retaining insert 34 in case 22 against any residual pressure in compartment 26 during ejection of the case in barrel 16.

Cartridge 56 functions similarly except that the gases for energizing the firearm operating mechanism (not shown) are bled into conduit 26 through apertures 60 which are located approximately where the discharge gases reach their peak pressure.

From the foregoing it is clearly apparent that there is provided herein a multiprojectile cartridge which includes internal means for tapping gases at peak pressure for operation of a firearm operating mechanism and which assures obturation between the cartridge and barrel and positive retention of the projectile holding insert in the fired case during ejection thereof.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. In cooperation with a gun barrel having a cartridge receiving chamber and an axial conduit and a plurality of bores extending therefrom, a cartridge having a case, an insert received by the front section of said case, a plurality of holes equal to the number of said bores extending through said insert, said holes being arranged so as to be coaxially alignable with said bores, a projectile received by each of said holes, a compartment formed in said case rearwardly of said insert for receiving a propellent, a means in said insert for discharging gases at peak pressure from the cartridge into said conduit, and including pneumatic means which aid in retaining said insert in said case against residual gas pressure in said compartment during ejection of said case from said chamher.

2. The cartridge as defined in claim 1 wherein said means for discharging gases at peak pressure from the cartridge into said conduit include a port formed in said insert so as to be in registry with said conduit when the cartridge is received by said chamber, and a diaphragm disposed between said port and said compartment, said diaphragm being designed for rupture by the discharge gases in said compartment when approximately at their peak pressure,

3. The cartridge as defined in claim 1 wherein said means for discharging gases at peak pressure from the cartridge into said conduit include a cylindrical recess centrally formed in the front face of said insert so as to intersect said holes at the front ends thereof and so as to be in registry with said conduit when the cartridge is received by said chamber, and an aperture formed by the intersection of said recess with each of said holes to provide communication between said compartment and said conduit approximately where the discharge gases are at peak pressure.

4. The cartridge as defined in claim 1 wherein said pneumatic means include a recess formed in the front face of said insert, a forwardly facing surface formed by said recess, said recess having a smaller area than the rear end of said insert, and means providing communication between said recess and the front end of said holes.

References Cited in the file of this patent UNITED STATES PATENTS 368,924 Krieger Aug. 23, 1887 588,764 Boss Aug. 24, 1897 2,537,443 Cerrella Jan. 9, 1951 2,974,592 Williams et al Mar. 14, 1961 

1. IN COOPERATION WITH A GUN BARREL HAVING A CARTRIDGE RECEIVING CHAMBER AND AN AXIAL CONDUIT AND A PLURALITY OF BORES EXTENDING THEREFROM, A CARTRIDGE HAVING A CASE, AN INSERT RECEIVED BY THE FRONT SECTION OF SAID CASE, A PLURALITY OF HOLES EQUAL TO THE NUMBER OF SAID BORES EXTENDING THROUGH SAID INSERT, SAID HOLES BEING ARRANGED SO AS TO BE COAXIALLY ALIGNABLE WITH SAID BORES, A PROJECTILE RECEIVED BY EACH OF SAID HOLES, A COMPARTMENT FORMED IN SAID CASE REARWARDLY OF SAID INSERT FOR RECEIVING A PROPELLENT, A MEANS IN SAID INSERT FOR DISCHARGING GASES AT PEAK PRESSURE FROM THE CARTRIDGE INTO SAID CONDUIT, AND INCLUDING PNEUMATIC MEANS WHICH AID IN RETAINING SAID INSERT IN SAID CASE AGAINST RESIDUAL GAS PRESSURE IN SAID COMPARTMENT DURING EJECTION OF SAID CASE FROM SAID CHAMBER. 